A vehicle, e.g., a car, truck, bus, etc., may be operated wholly or partly without human intervention, i.e., may be semi-autonomous or autonomous. For example, the vehicle may include sensors and the like that convey information to a central computer in the vehicle. The central computer may use received information to operate the vehicle, e.g., to make decisions concerning vehicle speed, course, etc. However, mechanisms are needed for evaluating a computer's ability to autonomously operate the vehicle, and for determining an action or actions to take when one or more faults are detected.